A while back, I wrote an article for the eLearning Guild which was essentially about measuring social media as a learning tool. We called social media "Learning 2.0" but the issue is the same. Here is the article.

I'm reprising that here, because I just read Ettiene Wenger's (2011) article where he talks about measuring social media, and I am once again disappointed that opportunity costs and costs of bad-information are not recognized.